This invention relates generally to a liquid supply system for a beverage dispenser. More particularly, the present invention comprises an apparatus for providing an undiluted mixture of syrup and water in a predetermined ratio for a beverage dispenser.
A liquid supply system of the general type embodied in the present invention, when used with a beverage dispenser, provides an automated means for operators or consumers to obtain beverages, such as soda, fruit juices, slushes or the like, which are made of a mixture of a predetermined ratio of water and a concentrate or syrup. Generally, it is important that the ratio of the water and syrup remain constant to provide a beverage of a generally consistent, uniform quality. The water flow is usually provided from a source such as a municipal water system and is regulated by a flow meter. The syrup is generally provided from a source such as a syrup container via a syrup pump which may be electrically powered. The beverage dispenser may receive the proportioned syrup and water for immediate mixing and direct dispensing of the beverage in the manner of a soda fountain or bar gun. Alternatively, the beverage dispenser may receive the mixed, proportioned syrup and water and store the mixed liquid in a storage container for display and for dispensing at a later time, in the manner of a juice or slush dispenser. The storage container may include a stirring mechanism to continually or periodically stir or agitate the liquids to maintain a homogeneous mixture.
With both of these types of beverage dispenser, however, problems are often encountered when the syrup source becomes low or depleted. Once the syrup source is low or depleted, little or no syrup enters the pump. If the beverage dispenser is of the type in which the beverage is dispensed directly as it is received from the pump, a diluted beverage or only water is dispensed. If the beverage dispenser is of the type utilizing a liquid storage container, the mixed beverage stored in the container becomes diluted due to the water being added to the container without a corresponding addition of syrup. Therefore, the ratio of syrup to water of the liquid within the storage container slowly becomes more and more disproportionate, each time the liquid supply system attempts to fill the container. In either type of beverage dispenser, the resulting beverage being dispensed is not of a consistent, uniform, acceptable quality. In the case of the direct dispenser, the problem may be noticed by the operator after one or more containers have been filled. In the case of a beverage dispenser with a storage container, the problem may not be noticed by the operator as quickly, particularly with a self-service dispenser, resulting in numerous dissatisfied customers and the need to dispose of the entire contents of the storage container.
A number of prior solutions have been proposed for preventing dispensing of diluted beverage when the syrup source becomes depleted. One such prior art solution involves the use of a float device attached to one end of a rod or string within the syrup container, the other end of the rod or string being attached to a cutoff switch associated with the pump. As the syrup in the container falls below a predetermined level, the float device moves downwardly, actuating the switch to cut off the pump and prevent the pumping of any more syrup. The switch also stops the flow of the water.
A similar prior device uses a float in the syrup container to block the syrup exit opening when the syrup falls below a certain level. The blocking of the exit opening produces a vacuum within the line running from the syrup to the pump to cut off the pump and to stop the flow of the water.
These prior art systems, as well as other prior art systems currently in use, are generally ineffective in that there is generally a significant delay between the time that the syrup supply becomes depleted below a proper operating level and the time that the pump and the water flow are actually cut off. Such a time delay results in the dispensing of watered-down beverages or the dilution of the mixed beverage in the storage container.
The present invention overcomes the problems of the prior art by providing a liquid supply system in which the pump provides both the syrup and the water and is immediately deactivated when a vacuum in excess of a predetermined limit is sensed within the syrup container. The predetermined vacuum limit is established to coincide with the depletion of the syrup within the container below a predetermined syrup limit sufficient to provide the required syrup to the pump to maintain the predetermined water/syrup ratio.